13 Incredible Movie Transformations That Will Astound You

It's always a bit of a shocker to hear what some actors are willing to endure in the name of "authentic performances," whether it's chopping off all their hair, sitting in a makeup chair for hours on end, or, in extreme cases, submitting to unorthodox dieting habits.

Despite some of the un-glamorous techniques, these movie transformations have astounded audiences all over the world and earned some of the performers the highest of honors. Here's a look back at 13 mind-blowing actor transformations in film.